Alpha Coronae Australis or α Coronae Australis, officially named Meridiana (), is the brightest

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Corona Australis Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-centu ...

and is located about 125

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

Nomenclature

''α Coronae Australis'' ( Latinised to ''Alpha Coronae Australis'') is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

. It is the only star in the constellation with a traditional proper name, ''Alphekka Meridiana'' (

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for 'Alphekka South'), after ''

Alphecca Alpha Coronae Borealis (α Coronae Borealis, abbreviated Alpha CrB, α CrB), officially named Alphecca , is an eclipsing binary star in the constellation of Corona Borealis. It is located about 75 light years from the Sun and contains tw ...

'', the brightest star in the constellation Corona Borealis. The name ''Alphecca'' or ''Alphekka'' is

Arabic Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...

, short for نير الفكّة ''nayyir al-fakka'' "the bright (star) of the broken (ring of stars)". In 2016, the IAU organized a

Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Meridiana'' for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, (), meaning '' River Turtle'', refers to an asterism consisting of Alpha Coronae Australis,

Alpha Telescopii Alpha Telescopii, Latinized from α Telescopii, is the brightest star in the southern constellation of Telescopium, with an apparent visual magnitude of 3.5. The ancient Roman astronomer Ptolemy included it in the constellation Corona Au ...

, Eta¹ Coronae Australis,

Zeta Coronae Australis Zeta Coronae Australis (ζ Coronae Australis) is a solitary, blue-white hued star located in the southern constellation Corona Australis. With an apparent visual magnitude of +4.75, it is sufficiently bright to be viewed with the naked eye. ...

Delta Coronae Australis Delta Coronae Australis is a single star located in the southern constellation of Corona Australis. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.57. The star is located about 174 l ...

Beta Coronae Australis Beta Coronae Australis (Beta CrA), Latinized from β Coronae Australis, is a solitary star located in the southern constellation Corona Australis. It is visible to the naked eye as a faint, orange-hued star with an apparent visual ...

Gamma Coronae Australis Gamma Coronae Australis (γ CrA), is a binary star located in the constellation Corona Australis. The system has a combined apparent visual magnitude of 4.20, making it faintly visible to the naked eye. It is located 56.4 light-years (17. ...

Epsilon Coronae Australis Epsilon Coronae Australis (ε CrA), is a star system located in the constellation Corona Australis. Varying in brightness between apparent magnitudes of 4.74 to 5 over 14 hours, it is the brightest W Ursae Majoris variable (low mass cont ...

, HD 175362, Kappa² Coronae Australis and Theta Coronae Australis. Consequently, the Chinese name for Alpha Coronae Australis itself is (, en, the Sixth Star of River Turtle.).香港太空館 - 研究資源 - 亮星中英對照表
, Hong Kong Space Museum. Accessed on line November 23, 2010.

Properties

Alpha Coronae Australis belongs to the spectral class A2Va, making it an A-type star like

Vega Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, an ...

. Like the latter, it has excess infrared radiation, which indicates it may be ringed by a disk of dust. It has an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

of +4.10. The star's mass and radius are estimated at 2.3 times the Sun's mass and

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

. With an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of roughly 9,100 K, the star radiates a total luminosity of about 31 times the Sun's. This star is roughly 254 million years old. A rapidly rotating star, it spins at almost 200 km per second at the equator, making a complete revolution in approximately 14 hours, close to its

breakup velocity A relationship breakup, breakup, or break-up is the termination of a relationship. The act is commonly termed "dumping omeone in slang when it is initiated by one partner. The term is less likely to be applied to a married couple, where a break ...

References

{{DEFAULTSORT:Alpha Coronae Australis A-type main-sequence stars Corona Australis Coronae Australis, Alpha Durchmusterung objects 178253 094114 7254

Meridiana Meridiana Fly S.p.A., operating as Meridiana (formerly named ''Meridiana S.p.A.''), was a privately owned Italian airline headquartered in Olbia with its main base at Olbia Costa Smeralda Airport. It operated scheduled and charter flights to do ...

Nomenclature

Properties

See also

References